Neisseria Meningitidis (the Meningococcus) has 13 serogroups, with A, B, C and W being the most common. I must admit I’d never heard of ‘Meningitis W’ before, but as you’ll read it’s a rare disease to be aware of.

Whilst meningitis W only accounts for approx. 15% of invasive meningococcal disease,﻿this paper﻿from December 2014 raised concerns about a rise in the UK incidence. Furthermore, the atypical presentation and severity of disease was worrying. Figure 1 shows this rise in cases against a background of an overall reduction in the incidence of invasive meningococcal disease.

Because the disease appeared to be prevalent in teenagers, this six month case review was conducted, limited to patients aged 15-19. The review found 15 cases; of the 7 presenting with gastrointestinal symptoms, 5 died within 24 hours of presenting to hospital.

The likelihood of a case of Group W meningococcal septicaemia presenting to Sunderland (or indeed anywhere) is still small, but the case series makes for harrowing reading.

As far as what we do with this information on a day to day basis, I’m not sure. After all, there are lots of well looking teenagers with GI upset who look well simply because they are, but early diagnosis is clearly vital.

Finally, the public health response is quite interesting to read about, as an insight into a specialty I know little about.

Childhood meningococcal vaccination for group C disease has now been around for some time and so this type of meningococcal infection is relatively rare. Group B vaccination is also available althouh not routinely used and has had some effect on the amount of Group B meningococcal disease presenting. Group A meningococcal disease is something that is known to be a risk from foreign travel and outbreaks have occurred during the Hajj pilgrimage. W 135 is another rarer serogroup that has been of concern mostly in travelling patients (including Hajj pilgrimage). There is a tetravalent A,C,W135, Y vaccine that is recommended for travellers to africa, far east, middle east and indian subcontinent.
At present there seems to be evidence that W135 is circulating within the UK and the previously 'rarer' serogroups may become more prevalent due to the effect of group B and C vaccination.
W 135 septicaemia tends to present with somewhat atypical features and gastrointestinal symptoms have been prominent - alongside non specific malaise and obtundation. When the diagnosis of meningococcal disease has not been considered at an early point, most patients have died. We have alerted colleagues in the main admission areas to look out for this kind of presentation, so do not be surprised if you get referrals with patients who may on initial assessment appear to have gastroenteritis, but may on careful examination appear generally sicker than you would expect for that diagnosis. Blood cultures and blood tests for DNA have been more helpful than CSF in diagnosing these cases, since the majority do not have meningitis. Septic arthritis has been another of the unusual ways this disease presents.